Vibration and Noise of an Axial Flow Fan

We describe a mechanical/acoustic study of a short-ducted axial flow fan. The purpose is to compare mechanical noise to that caused by flow phenomena.The eigenfrequencies of the fan are identified through measurement and finite element computations. The fan acoustics is evaluated by beamforming studies using the Phased Array Microphone technique. The acoustic measurement data is processed by the Rotating Source Identifier method. The modal analysis of the fan model and the acoustic experiments reveal that the fan noise is dominated by mechanical noise in the few hundred Hz range and rotating sources of broadband noise above